Assay of α-glucosidase inhibitory activity using flow-biosensor system

Kiyoshi Matsumoto, Kiyofumi Takayama, Kanthi J.M. Abesundara, Toshiro Matsui

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


A convenient and continuous method for the assay of α-glucosidase (AGH) inhibitory activity was developed using a continuous-flow/stopped-flow system combined with biosensors. The amount of glucose liberated from maltose by the action of AGH was quantified by an immobilized glucose oxidase (GOD) reactor with a Clark oxygen sensor in the downstream. The immobilized AGH reactor was set in the flow-line. When an inhibitor containing 10mM maltose substrate was injected and as it reaches the center of the immobilized AGH reactor, the working solution (synthetic intestinal fluid) was stopped for a certain period. After the reaction of inhibitor and/or substrate with AGH, the working solution was propelled again, and the glucose liberated was passed through the immobilized GOD reactor. The inhibition ratios (%) were calculated as the percent inhibition, which were the glucose concentrations in the presence of maltose and inhibitor divided by those in the presence of maltose alone. The multi-channel stopped-flow (MCSF) system was also developed, in which a seven-port, six-positioned rotary valve was inserted and six immobilized AGH reactors were set in a parallel configuration. The IC50 values of acarbose and 1-deoxynojirimycin, a medicinal inhibitor for diabetes, were 0.46±0.062 and 0.23±0.031μM, respectively, and coincided well with those by our pseudo-in vivo method [Biol. Pharm. Bull. 232 (2000) 1084]. The time to assay the inhibitory activity of one unknown sample was estimated to be 11min by the 6-channel modified-MCFS system. The proposed MCFS system offers a useful method to evaluate the inhibitory activity for AGH.

Original languageEnglish
Pages (from-to)135-141
Number of pages7
JournalAnalytica Chimica Acta
Issue number2
Publication statusPublished - Mar 10 2003

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry
  • Biochemistry
  • Environmental Chemistry
  • Spectroscopy


Dive into the research topics of 'Assay of α-glucosidase inhibitory activity using flow-biosensor system'. Together they form a unique fingerprint.

Cite this